Jig for sharpening jointer blades and the like

ABSTRACT

A jig mountable directly on a woodworking machine and incorporating guide means for reception and guiding of a blade grinding tool. The device includes an indexing collar permanently affixed to the cutterhead shaft and selectively locked into rotatably adjusted positions for a sequential alignment of the blades with the jig guided tool.

United States Patent Smith 6161.

15] 3,691,702 1 51 Sept. 19, 1972 [54] J [G FOR SHARPENING JOINTER BLADES AND THE LIKE [72] Inventors: Howard J. Smith, 1212 N. Delaware Ave.; Byron F. Smith, 901 Pecon Drive, both of Roswell, N. Mex. 88201 v [22] Filed: Nov. 17, 1970 [21] App1.No.: 90,326

[52] U.S.Cl. ..51/249 [51] Int. Cl. ..B24b 3/38 [58] Field ofSearch .5l/246,249,173

[56] References Cited I UNITED STATES PATENTS 962,047 6/1910 Peterson ..'......-51/249 3,354,589 11/1967 Postula et a1. ..51/249 3,149,444 9/1964 Schneider ..51/249 Buttke..' ..51/249 1,074,739 10/1913 Pixley.... ..51/249 2,944,376 7/1960 BUttRC... ..51/249 3,581,446 I 6/1971 Witt et a] ..s1/249 2,729,923 1/1956 Durst ..51/249 Primary Examiner-Donald G. Kelly ArtorneyClarence A. O'Brien and Harvey B. Jacobson [57] ABSTRACT A jig mountable directly on a woodworking machine I and incorporating guide .means for reception and guiding of a blade grinding tool. The device includes an indexing collar pennanently affixed to the cutterhead shaft and selectively locked into rotatably adjusted positions for a sequential alignment of the blades with the jig guided tool. j 1 1 6 Claims, 5 bre ing Figures PATENTED EP I9 INVESTORS.

Byron F Smith Howard J. Smith JIG FOR SHARPENING JOINTER BLADES AND THE LIKE The instant invention is generally concerned with the provision of means for sharpening the blades of woodworking machines such as jointers, planers, and the like, and more particularly relates to a jig mountable directly on the machine for a guiding of the grinding tool or implement relative to the mounted blades.

It is a primary object of the instant invention to provide a device which enables the sharpening of the blades of a woodworking machine directly on the machine itself, thereby avoiding the necessity for removing and subsequently remounting the blades.

In conjunction with the above object, it is also a significant object of the instant invention to provide a device whereby the machine mounted blades are locked in position during the sharpening operation with each of the blades being sequentially moved into sharpening position relative to the fixed location of the grinding wheel whereby a matched grinding of the blades can be easily effected.

Also of significance with regard to the instant invention is the structural simplicity of the jig which results in both an economically feasible unit and a device which can be both easily and quickly mounted and adjusted as required.

In conjunction with the above objects, it is an important feature of the invention to provide a device which, notwithstanding the simplicity thereof, constitutes a unique means for accommodating and exactly guiding a grinding implement relative to machine mounted blades which are temporarily fixed in sharpening position by the tool guiding device itself.

The above objects are achieved basically through the provision of a jig which incorporates elongated base plates positionable transversely across a machine parallel and to the opposite sides of the blade mounting cutting head. These plates mount opposed upright guides which receive the grinding tool therebetween for movement along the blades. In addition, an indexing collar is affixed to the cutting head shaft and selectively locked to an overlying portion of the jig so as to fix each blade in an upwardly directed orientation for engagement by the grinding tool.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of a woodworking machine with the jig of the instant invention mounted thereon;

FIG. 2 is an enlarged cross-sectional detail taken Substantially on a plane passing along line 2--2 in FIG. 1;

FIG. 3 is a cross-sectional detail taken substantially on a plane passing along line 33 in FIG. 2;

FIG. 4 is a cross-sectional detail taken substantially on a plane passing along line 4-4 in FIG. 1; and

FIG. 5 is a cross-sectional detail taken substantially on a plane passing along line 55 in FIG. 1.

Referring now more specifically to the drawings, reference numeral is used to generally designate the jig comprising the instant invention. The jig 10, as will be appreciated from FIG. 1, is adapted to mount transversely across a woodworking machine 12, for example a jointer or planer, and rest on the longitudinally aligned table sections 14 with the blade mounting cutterhead 16 centrally located therein.

The jig 10 includes a pair of flat elongated base plates 18 orientated in laterally spaced coplanar parallel relation to each other. These base plates 18 are to be orientated transversely across the machine 12 and are of a length so as to project beyond the opposed or front and rear sides thereof. Interconnecting the front and rear ends of the base plates 18 are a pair of connecting bars 20 and 22. The bar 20 is of a generally U-shaped configuration with the free ends thereof bolted or otherwise affixed to the lower faces of the base plates 18 at the forward ends thereof. The central portion of the connecting bar 20 is recessed below the plane of the base plates 18 so as to allow free access therebetween should such be necessary in the introduction and removal of the grinding or sharpening tool 24.

The rear connecting bar 22 has the opposed end portions thereof affixed to the upper surfaces of the base plates 18 at the rear ends thereof with the central portion of the connecting bar 22 having a downwardly directed generally arcuate recess 26 defined therein.

Each of the base plates 18 has an elongated guide 28 mounted thereon. These guides 28 are preferably formed of angle members having a vertically directed guiding flange 30 and a-laterally outward projecting horizontal mounting flange 32. Each of the guide mounting flanges 32 includes a pair of elongated slots 34 provided therein toward the opposed ends thereof. These slots in turn receive mounting bolts 36 therethrough which bolts are received within internally threaded holes provided in the underlying portion of the corresponding base plate 18. In this manner, through a selective loosening of the bolts 36 and sliding of the guides 28, a lateral adjustment of the guides can be effected within the range of the length of the slots 34. Once adjusted, the bolts 36 will be tightened so as to firmly lock the guides 28 in position. Inasmuch as the grinding tool 24 is to rest on and guide along the inwardly directed longitudinal portions of the opposed base plates 18, it will be appreciated that the opposed guides 28 are outwardly offset on the base plates a sufficient distance so as to provide their guiding function while at the same time exposing a sufficient width of each base plate 18 so as to support the tool 24.

The jig is both adjustably and releasably affixed to the machine 12 by means of a pair of opposed mounting lugs 38, one engaged with the outer edge portion of each of the base plates 18. Each of the lugs 38. includes a rabbeted end which overlaps the corresponding base plate, and a relatively longer body portion which includes an elongated bolt accommodating slot 40 therethrough. The slot 40 in turn receives an elongated threaded bolt 42 which is threaded into an internally threaded bore provided in the corresponding table section 14 of the machine 12.

It is of course essential to properly orientate the cutterhead 16 so as to selectively position the blades 44 for engagement by the grinding or sharpening tool 24. In order to effect this, the drive pulley on the cutterhead shaft 46 is replaced by a specifically constructed pulley 48 incorporating a laterally projecting integral hub 50. This hub 50 in turn mounts an indexing wheel or collar 52. The collar 52 includes a series of internally threaded bores 54 radially therein at spaced points thereabout corresponding with the spacing of the blades 44 about the cutterhead 16. The collar 52 is rotated on the hub 50 to a position wherein the bores 54 are in alignment with the blades 44, at which point the collar 52 is locked to hub 50 by appropriate setscrew means or the like 56. The indexing collar 52, upon a mounting of the jig l0, aligns vertically beneath the central recess 26 in the connecting bar 22 for a selective engagement of the threaded lower end of a positioning bolt or shaft 58 which is slidably and rotatably mounted within a vertical bore 60 provided through the connecting bar 22 centrally thereof. This bolt or shaft 58, for ease of manipulation, includes an enlarged gripping head 62 on the upper end thereof.

In using the jig of the instant invention, the opposed table sections 14 are adjusted to coplanar orientation with each other and the jig positioned transversely thereacross with the base plates 18 resting on the inner portions of the two sections 14 with the cutterhead received therebetween. .The cutterhead 16 is rotated so as to align one'of the bores 54 with the positioning bolt 58, after which the positioning bolt 58 is locked into the aligned bore 54 to fix the corresponding blade 44 in position for engagement by the grinding tool 24. The jig is then squared with the top of the machine 12 or orientated so as to parallel the initially positioned blade 44, after which the jig isflocked the position by the mounting lugs 38. If deemed necessary, at this point the opposed guides28 can be adjusted also. The grinding tool 24, which can be router with a grinding stone mounted thereon, is then positioned onthe jig and adjusted so as to bring the grinding head or stone into light engagement with the exposed blade, after which the tool 24 is manipulated along the jig to effect successive passes over the blade until the desireddegree of sharpness is achieved. Subsequent to a sharpening of this initially positioned blade, the positioning bolt 58 isbacked off and the cutterhead rotated so as to expose another blade, after which the positioning bolt is re-engaged to lock the cutterhead in position and the sharpening step is then commenced in connection with the newly positioned blade. This procedure is repeated until all of the blades have been sharpened with the sharpened blades perfectly matching. .Incidentally, it should be appreciated that the indexing wheel or collar 52 will remain on the cutterhead shaft 46 subsequent to the removal of the jig l0 and during the conventional operation of the machine 12. In this manner, the alignment of the bores 54 with the blades 44 will be maintained and the machine will in efl'ect be set up for again receiving the jig l0 when'a further sharpening of the blades is required. While, it is preferred that the indexing collar 52 be mounted on the shaft 46 through the pulley hub 50, if so desired, the collar 52 can be so constructed as to mount directly on the shaft 46 itself.

From the foregoing, it should be appreciated that a simple although highly unique device has been defined for positioning and guiding a grinding tool relative to machine mounted blades for a sequential sharpening of the blades in a manner whereby a perfectly matched set of blades is obtained.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

We claim: I

l. A device for guiding a blade sharpening tool over a machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the too], said jig comprising a pair of .laterally spaced plate means positionable transversely across the machine to the opposite sides of the upwardly directed blade, connecting means extending between and connecting said spaced plate means, said connecting means comprising bars extending between the corresponding ends of the spaced plate means at the opposed ends thereof, one of said bars between said plate means being downwardly offset relative to said plate means, a pair of tool guides, one guide positioned longitudinally along the upper surface of each plate means, and means mounting said guides for lateral adjustment relative to each other on said plate means, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar including indexing means thereon positionable to correspond in location to the blades, means for locking said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar, shaft and blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising internally threaded bores in said collar, said means engaged with said indexing means comprising a threaded bolt received through one of said connecting bars positioned in overlying relation to said collar.

2. A device for guiding a blade sharpening tool over a -machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the tool, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar including indexing means thereon positionable to correspond in location to the blades, means for locking said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar, shaft and blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising internally threaded bores provided at spaced point peripherally about said collar, said means engaged with said indexing means comprising a threaded bolt mounted on and depending from said jig for selective engagement with said bores.

3. The device of claim 2 wherein said jig comprises a pair of laterally spaced plate means positionable transversely across the machine generally parallel to and to the opposite sides of the upwardly directed blade, and

connecting means extending between and connecting said spaced plate means, said connecting means comprising at least one bar positionable in overlying relation to said collar, said threaded bolt mounting on and depending from said collar overlying bar.

4. The device of claim 3 wherein said bar extends between and interconnects a first pair of ends of the spaced plate means, said connecting means including a second bar extending between the second corresponding pair of ends of the plate means, said second bar being downwardly offset relative to said plate means to enable free access for introduction of a tool between the spaced plate means.

5. A device for guiding a blade sharpening tool over a machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the tool, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar ineluding indexing means thereon positionable to correspond in location to the blades, means for locking.

said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar shaft and blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising bores provided at spaced points peripherally about said collar, said means engaged with said indexing means comprising a shaft mounted on and depending from said jig for selective engagement with said bores.

6. The device of claim 4 wherein said jig comprises a pair of laterally spaced plate means positionable transversely across the machine to the opposite sides of the upwardly directed blade, connecting means extending between and connecting said spaced plate means, said connecting means comprising bars extending between 

1. A device for guiding a blade sharpening tool over a machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the tool, said jig comprising a pair of laterally spaced plate means positionable transversely across the machine to the opposite sides of the upwardly directed blade, connecting means extending between and connecting said spaced plate means, said connecting means comprising bars extending between the corresponding ends of the spaced plate means at the opposed ends thereof, one of said bars between said plate means being downwardly offset relative to said plate means, a pair of tool guides, one guide positioned longitudinally along the upper surface of each plate means, and means mounting said guides for lateral adjustment relative to each other on said plate means, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar including indexing means thereon positionable to correspond in location to the blades, means for locking said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar, shaft and blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising internally threaded bores in said collar, said means engaged with said indexing means comprising a threaded bolt received through one of said connecting bars positioned in overlying relation to said collar.
 2. A device for guiding a blade sharpening tool over a machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the tool, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar including indexing means thereon positionable to correspond in location to the blades, means for locking said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar, shaft and blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising internally threaded bores provided at spaced point peripherally about said collar, said means engaged with said indexing means comprising a threaded bolt mounted on and depending from said jig for selective engagement with said bores.
 3. The device of claim 2 wherein said jig comprises a pair of laterally spaced plate means positionable transversely across the machine generally parallel to and to the opposite sides of the upwardly directed blade, and connecting means extending between and connecting said spaced plate means, said connecting means comprising at least one bar positionable in overlying relation to said collar, said threaded bolt mounting on and depending from said collar overlying bar.
 4. The device of claim 3 wherein said bar extends between and interconnects a first pair of ends of the spaced plate means, said connecting means including a second bar extending between the second corresponding pair of ends of the plate means, said second bar being downwardly offset relative to said plate means to enable free access for introduction of a tool between the spaced plate means.
 5. A device for guiding a blade sharpening tool over a machine incorporating shaft mounted blades, said device comprising a tool accommodating jig, mounting means for fixing said jig to the machine in overlying relation to the machine blades for movement of the tool thereover, and positioning means for selectively locking the machine blades, one at a time, in an upwardly directed orientation for engagement by the tool, said positioning means comprising an indexing collar lockable on the blade mounting shaft, said collar including indexing means thereon positionable to correspond in location to the blades, means for locking said collar to the shaft, and means on said jig selectively engageable with said indexing means for fixing the collar shaft anD blades in a predetermined position with one of the blades upwardly directed, said indexing means comprising bores provided at spaced points peripherally about said collar, said means engaged with said indexing means comprising a shaft mounted on and depending from said jig for selective engagement with said bores.
 6. The device of claim 4 wherein said jig comprises a pair of laterally spaced plate means positionable transversely across the machine to the opposite sides of the upwardly directed blade, connecting means extending between and connecting said spaced plate means, said connecting means comprising bars extending between the corresponding ends of the spaced plate means at the opposed ends thereof, one of said bars between said plate means being downwardly offset relative to said plate means. 